Apparatus for separating trash from lint cotton and the like



une 22, 1954 W. VA APPARATUS FOR SEPARATING TRASH N DOORN 2,681,477

FROM LINT COTTON AND THE LIKE Filed Aug. 25, 1950 4 Sheets-Sheet l i /6 l i INVENTOR.

Fi i

.4 TTOR/VE Y5 June 22, 1954 wjv DQORN 2,681,477

APPARATUS FOR SEPARATING TRASH FROM LINT COTTON AND THE LIKE 4 Sheets-Sheet 2 Filed Aug. 23, 1950 INVENTOR. 00449401. mm 0004* June 1954 D. w. VAN DOORN 2,681,477

APPARATUS FOR SEPARATING TRASH FROM LINT COTTON AND THE LIKE Filed Aug. 23, 1950 4 Sheets-Sheet 5 4-7 h \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\Q i '"INVENTOR 00/1040 m VAW 0 M ATTORNEYS June 22, 1954 D. w. VAN DQORN ,68 77 APPARATUS FOR SEPARATING TRASH FROM LINT COTTON AND THE L IKE Filed Aug. 23. 1950 4 Sheets-Sheet 4 M fan ante/ways Patented June 22, 1954 APPARATUS FOR SEPARATIN G TRASH FROM LINT COTTON AND THE LIKE Donald W. Van Doorn, Columbus, Ga., assignor to Lummus Cotton Gin Company, a corporation of Georgia Application August 23, 1950, Serial No. 180,996

4 Claims. l

The present invention is an improvement over that disclosed in my co-pending application, Serial No. 115,204, filed September 12, 1949, subject Method and Apparatus for Separating Trash from Lint Cotton and the Like.

Heretofore in the art to which this invention relates, it has been proposed to utilize the combined effects of centrifugal force and gravity to separate trash from lint cotton and the like while the commingled trash and cotton were air-borne, as for instance while borne along by an air stream in the lint flue. Such methods of separation have not proved to be entirely satisfactory. One reason for this appears to be that the specific gravities of the lint and a large part of the trash mixed therewith are approximately the same. Thus, a centrifugal separator capable of discharging such trash also discharges therewith an excessive quantity of lint. Another reason for the lack of success of centrifugal-gravity separators for these materials is that in those types embodying slotted side walls the lint chokes the slots, makin the device inoperative after a short period of use unless the slots are frequently cleaned. In the mechanical type of cleaners embodying saws and cleaning bars, the saws appear to engage the cotton in such manner as to form snarled or tightly bunched groups of fibers which adversely affect the making of yarn from such lint. Also, considerable mechanical difficulty is encountered in properly sealing the condensers which are supposed to supply the cotton in a bat form to the saws of the prior art mechanical cleaners. Further, mechanical cleaners are expensive of manufacture and operation.

It is the prime object of my invention, therefore, to effect a greatly improved separation of air-borne trash and lint cotton, and to accomplish this separation with simple apparatus especially adapted for insertion in the lint flue between the gin and condenser.

Another object is to provide apparatus of the character designated which is further characterized by the introduction into the confined space of an auxiliary or booster jet of high velocity air ahead of the point therein where the lint and trash are separated, thus increasin the velocity of the commingled stream and blooming or openin the lint, thus disentangling trash bound therein, and in this manner facilitating the separating of the lint and trash.

Another object is to provide apparatus of the character designated in which the lint and trash at the point of separation thereof are subjected to a transversely directed, high velocity, low

volume stream of air under positive pressure operable to turn the lint and inoperable to turn the trash, such an air stream serving the purpose, among others, of drivin the lint with a high velocity toward another abrupt turn in the confined space Where the same may be subjected to another separating action. This transverse positive air stream eliminates the need of maintaining the lint discharge space of the first turn under vacuum and therefore makes it possible to have a second turn with both turns operating under optimum conditions of velocity and pressure.

Another object is to provide lint cleaning apparatus in which the commingled, air-borne lint and trash are introduced into a downwardly directed lint duct, there being a second lint duct adjacent the lower end of the first duct angularly disposed relative thereto, together with an openin at the adjacent ends of the lint ducts whereby, when commingled lint and trash are introduced into the first duct under the conditions hereinafter set forth the trash continues its downward movement, passing through the slot and out of the lint duct and the lint turns into the second duct, such construction eliminating drawing back into the lint duct of trash more or less suspended in the atmosphere immediately adjacent the outside of the lint duct, near the slot.

Another object is to provide apparatus of the character designated in which the comming-led lint and trash stream, just prior to reaching and while substantially at the trash discharge opening is subjected to auxiliary jets of air under pressure, the first jet being directed into the lint-trash stream in a direction toward which the same is moving, the second jet being directed somewhat transversely of the movin stream, the velocity of the second jet being suflicient to aid in changing the direction of movement of the lint and insufficient to change materially the direction of movement of the trash.

Another object is to provide apparatus of the character described in which there is introduced into the inlet section of the lint duct ahead of the trash discharge opening, a jet of air operable to increase the velocity of the commingled linttrash stream and also operable to drive toward the cleaning opening some of the heavy, low surface area trash which tends to settle on. the bottom of the entering .duct, thus making my improvedapparatussuitable for use with brush type gins and in those gins embodying pneumatic dofiing mechanism delivering dofling air at low velocities.

Qther objects of my invention are to make provision for adjusting the size or the trash discharge opening, preferably by adjusting the position of the knife edged member previously mentioned; to provide a housing into which the trash is discharged and having trash removing means therein; to so design the apparatus that the lint flue may be placed within the confines thereof, eliminating the necessity of excavating the floor of the gin house or of installing the lint flue under the floor; and in general to provide apparatus which is particularly free of structural complications and which is simple of installation and operation.

Apparatus illustrating the features of my in vention is illustrated in the accompanying drawings forming a part of this application in which:

Fig. 1 is a side elevational view partly in section of a gin, its associated feeder, and my improved apparatus between the gin and condenser;

Fig. 2 is a plan View, partly broken away and in section of the gin and feeder and my improved apparatus associated therewith;

Fig. 3 is an enlarged vertical sectional view through my improved separating apparatus with certain parts broken away for the sake of clarity;

Fig. 4 is a vertical sectional View through a modified form of my invention embodying the booster and transverse jets, the downwardly directed lint receiving duct, and in which the lint fine is disposed within the confines of the a paratus;

Fig. 5 is an enlarged detail sectional view of the adjustable wall having the sharpened edge adjacent thetrash slot employed with the apparatus shown in Fig. 4;

Fig. 6 is a fragmental sectional view taken generally along line VI--VI of Fig. 5;

Fig. '7 is a fragmental end elevational view of the operating handle and locking member there for for the adjustable sharpened wall of the apparatus shown in Fig. 4;

Fig. 8 is a detail sectional view taken along line VIII-VIII of Fig. 7;

Fig. 9 is a wholly diagrammatic view illustrating the functioning of the apparatus shown in Fig. 4; and

Fig. 10 is a fragmentary side elevational view of a duct leading from the gin and embodying means for introducing an additional jet of air into the same ahead of the cleaning apparatus.

Referring now to the drawings for a better understanding of my invention and more par ticularly to Figs. 1, 2 and 3, I show at iii the usual gin stand embodying a rotating saw cylinder H. Adjacent the saw cylinder is an air chamber 82 which supplies air through a doiiing nozzle 53 for removing lint cotton from the saw cylinder H. Beneath the saw cylinder is a lint duct i i. Lint from the saws is discharged into the lint duct i i in the manner well understood in the art. While only one gin stand is shown in the drawing, it will later appear that my invention is adapted for association with each gin of a multiple number thereof. Thus, lint from the separate gins it is eventually delivered through a system of ducts from the duct M to a common lint flue Q8. The lint duct id is of a width corresponding substantially to the length of the saw cylinder H, as shown in Fig. 2. Also, the doffing nozzle 13 as is well understood, extends along the saw cylinder and discharges into the duct 14. From the lint duct i i the lint heretofore has been discharged into a battery condenser if there is more than one gin, or to an individual condenser 4 if that is desirable, which would be the case in the event there was but a single gin. The condenser i'i of the usual type and may embody a rotary foraminous drum l8. Connected to the condenser to exert suction on the drum l8 and thence on the lint flue i6 is a suction fan 19.

My invention preferably is associated with a substantially closed housing indicated generally by the numeral 2 i. As shown in Figs. 1 and 3 the housing has a rear wall 22, a front wall embodying sloping sections 23 and 24 and end walls 21 and 28. There is also a top wall 29 extending partially across the top of the apparatus and the same terminates to provide an opening 39 therein. A partially extending vertical wall 3| depends from the edge or" the opening 30. For the sake of observing the apparatus in operation I may provide glass observation windows or ports {-32 in the sloping wall section 2d, and may also light the interior of the housing by means of a fluorescent tube 53 or the like. At 34 is a partially extending wall which converges toward the wall 23 to form therewith a hopper bottom. A trash discharge belt 36 may be provided in the hopper bottom formed by the walls 34 and 23.

Within the housing 2! and passing beneath the lower end of the wall 22 and over the upper end of wall 3 5 is a relatively wide, shallow lint duct 3'! into which lint from the gin H! is delivered from the associated gin lint duct 14. The lint duct 3? comprises an upper wall 38 and a lower wall as spaced above the upper end of wall 34. The walls 38 and 39 converge toward each other adjacent the inner end of the duct 3i, the wall 38 preferably being substantially straight and the wall as curving slightly upwards as shown. This construction provides a constricted throat or passage ll adjacent the inner end of the duct 31. In practice I have found that the curved, converging end of the duct 3i causes the lint and trash moving in the duct 3? to move against the wall 33, concentrating the lint and trash into a relatively thin ribbon. As will later appear, the cross stream of air entering the duct acts uniformly on this thin ribbon, increasing the cleaning action of the apparatus.

The inner end of the wall 39 has a depending portion M which may be suitably secured to a cross rod l3 in turn projecting through slots 44 in the housing ends 27 and 28. The rod is adjustably secured at each end by means of nuts, not shown, whereby the inner end of the wall 39 may be adjusted toward and from the inner end of the wall 38. Cover plates 58 in the form of washers may be placed about the ends of the rod 13 to close the slots 46.

The wall 33 of duct 3? continues upwardly as at 46 at an angle to that portion thereof forming a part of duct 3?. Preferably, the angle between the wall portions 38 and it is not greater than On the end of the wall it is a channel shaped extension 47 within which is placed the free end 48 of a wall d9 forming in effect a continuation of the wall as. A second wall 5! co-acts with the wall as to form a laterally elongated lint discharge section 52.

Rotatably supported in the end walls of the housing is a cross shaft 53. At intervals along the cross shaft are secured arms 54. Secured to the lower side of the wall section 33 adjacent the channel shaped extension thereof is a cross member 56. Pivotally connected to the ends of the arms 54 and the cross member 56 are links 51.

The cross shaft 53 projects from one of the housing ends and secured to the projecting end thereof is an operating arm 58. It will thus be apparent that by rotating the arm 58, shaft 53 may be rotated, thus moving the free upper edge of the wall portion 46 to the dotted line position indicated in the drawings, Fig. 3. The ends of wall section 50 fit closely against the end walls 21 and 28 of the housing making the duct 52 substantially airtight at those points. This serves to adjust the cross sectional area of theduct 52 at the point indicated.

The wall 5|has a straight lower section are terminating at 50. Fitting slidably about the lowerend 5Ia ofthe wall 5i is a U-shaped plate B l. Secured to the top of the plate 6i at each end thereof to slideagainst the end walls 21 and 28 of the housing are upstanding brackets 62. The brackets 02 ar provided with slots 63 in the ends thereof which slidably receive inwardly projecting pins 64 carried by the end walls 21 and 28.

Suitably journaled in the end walls of the housing is another cross shaft 60. Secured to the cross shaft 60- and pivotally secured to the brackets 62 are arms 61. Projecting upwardly from the shaft 66 is an operating rod 68 by means of which the shaft 66 may be rotated.

Secured to the lower ends of the brackets 62 is an adjustable section 09 forming in effect a continuation of the upper wall 5|. The lower portion of the wall 59 is bent inwardly toward the wall sections 38 and 46- thus to define a somewhat constricted portion in the duct 52 at its lower end. The lower edge 1! of the Wall 69 is sharpened. The edge 1| of the wall section 69 and the innermost edge 12 of the wall 39 define between them a trash discharge opening 13 through which trash is discharged in the manner later to appear. It will be understood that the opening 13 is substantially the width of the ducts 31 and 52, and that the latter are substantially as wide as the doiiin mechanism of the gin.

From the foregoing the method of operation of m improved apparatus may now be described. With the gin l delivering commingled lint cotton and trash through the duct I4 and into the duct 31 it will be apparent that the velocity of the commingled stream is substantially increased at the constricted point 4| in the duct 31, just ahead of the trash discharge opening 13. With a certain type of 80 saw gin delivering approximately 3000 cubic feet of commingled lint trash and air per minute into the duct 31, I find that there is a pressure of approximately one inch on the water gauge at the inlet end of duct 31. Under these conditions I so regulate the suction fan [9 that there exists in the duct 52 a vacuum of approximately 2 inches on the water gauge. I adjust the lower wall 30 relative to the upper wall 38 so that the commingled stream at the point 41 is moving at the rate of approximately 6000 feet per minute. Further, I so adjust the movable wall section 50 that the slot 13 is approximately 1% inches in width. In actual practice, I have found that with an 80 saw gin supplying approximately 3000 cubic feet per minute of air and lint with its impurities to the duct 31 the threat at the point il should be approximately inch to 1 inch when using ducts 31 and 2 which are 3 inches in depth at their inlet and discharge ends, respectively. In this instance, the width of the ducts 31 and 52 was the patent application of Arvel L. Vandergriff, 1

Serial No. 36,935, filed July 3, 1948, subject Pneumatic Dofiing Mechanism for Cotton Ginsand the Like, now Patent Number 2,588,593, I find that there is some variation in the delivery pressures and volumes which necessitates slight adjustments in my improved apparatus. The reason for this is that the type of gin disclosed in this application supplies considerably less dofilng air and does not operate as successfully under pressure much in excess of .4. inch on the water gauge. Actually, with such a gin I find that the volume of commingled lint, trash and air supplied to the duct 31 is on the order of 1800 cubic feet per minute, and under a pressure of approximately inch on the water gauge. With this gin, therefore, I adjust the wall 39 so that the velocity of the commingled lint and trash at the point ll is in the neighborhood of 4000 feet per minute. I further so regulate the fan l9 that there exists in the duct 52 a vacuum of approximately 1 /2 inches on the water gauge.

While in actual practice I have found it seldom necessary to constrict the duct 52 by means of the adjustable mechanism embodying the operating handle 58, this feature is desirable for certain types of cotton cleaning operations. At all events, and with the apparatus operating under the conditions just given for either type of gin with which it may be employed I have found that there is induced into the trash discharge opening 13 a volume of air moving at a velocity sufficient to cause the lint traveling in the duct 31 adjacent the point 41 thereof to assume-an upward direction of movement, and yet which is insufiicient to prevent the trash from continuing along substantially its initial direction of movement, thus to be discharged over the inner end 12 of the lower wall 39, out of the slot 13. This induced air is drawn downwardly through the opening of the housing. Further, there is induced betweenthe upper end of the wall 3 and the wall 39 a small volume of air indicated by the arrows which rinses the inner surface of the wall 34 of trash accumulating thereon, causing it to fall onto the belt 36. I estimatethat the volume of air induced into the openin 13 is equal to approximately 2000 cubic feet per minute when employing the gin delivering the greater volume of air, lint and trash into the duct 31, and approximately 1600 cubic feet per minute when employing the .gin delivering the smaller volume of air, lint and trash into the duct 31.

In lint cotton as it comes from the gin, there are usually bunches or wads of lint, and some lint which is wrapped about particles of trash. I have found that with the apparatus operating as just set forth the majority of these bunches of lint strike the knife sharp edge 1| of the wall section 69. The effect of this is to strip a large quantity of this lint from the trash or to untangle the same if it is bunched. Further, once the trash is disentangled or disengaged from the foreign matter about which it is wrapped thelint proceeds up the duct 52 and a large portion of the trash follows the trash stream out or the trash discharge opening 13. The sharpened edge 1! thus serves as a divider piece for the streams of lint and trash and likewise serves the purpose of disengaging or disentangling the bunched lint. Observing the apparatus in operation I note that the lint in fact impinges against the sharp edge 1! and appears, in high speed photographs, to momentarily drape over the sharpened edge 11 of wall 59-. However, the amount of lint which follows the trash stream is negligible and I have effectively separated a large part of both the heavy and fine trash such as is ordinarily mixed with cotton without any appreciable loss of lint. In actual practice I find that the average weight of lint thrown out by my apparatus is only about of the Weight of the trash removed, a figure which is far below the amount thrown out by other types of cleaners.

Referring now more particularly to Figs. 4 to 9, inclusive, I show a modified form of my improved apparatus. This form of apparatus embodies generally an upper separating section A and a lower separating section B. As will later appear, both sections A and B embody the principles of the apparatus already described.

The air-borne commingled lint cotton and trash from the gin is introduced into an upwardly directed, laterally elongated, curved duct 16 embodying an upper or outer wall i1 and an inner or lower wall IS. The duct Iii is preferably substantially the width of the air dofiln nozzle of the gin. The upper wall ll terminates at I9 and carries a plurality of upstanding studs SI near the end thereof. Spaced from the end 19 of the wall ll is an inclined plate 82 suitably supported from a vertically disposed Wall 83 in turn carried by the end walls 88 of the apparatus. Projecting normally from the surface of the plate 82 are a plurality of studs 84. Adjustably mounted on the studs 81 and Ed by means of nuts 86 are brackets 8'! and 88. The brackets are secured to the end of a vertically adjustable, slightly curved plate 39 forming in effect a continuation of the upper wall ll. The section 8i) is thus vertically adjustable relative to the wall 18 by means of the nuts 86. The inner end of the plate 89, namely the end supported from the studs 84, is so adjusted that it lies closer to the lower wall 78 than the outer end thereof, thereby to define a constricted passage 9! in the duct 16.

Extending longitudinally of the apparatus is an airsupply pipe 92. The pipe 92 communicates with a closed space 533 located above the adjustable wall section 89 which is defined between the walls 83, the end walls 89 of the apparatus and a removable cover plate 94. The space 93 is an air chamber to which air under pressure from any suitable source, not shown, is admitted from the air supply pipe 92. The edges of the movable wall section 83 define with the end IQ of wall 18 and lower end of the plate 82 a pair of air discharge Openings or nozzles Q6 and 91. Air from the nozzle 86 is directed into the duct I6 in a direction substantially parallel to the direction of movement of the commingled lint-trash stream therein. Air from the nozzle 91 is directed somewhat transversely of the moving stream as will later appear.

The lower wall I3 of the duct 16 is abruptly turned as indicated at 98 to provide a portion 99 forming one wall of a second duct Itll. The wall 99 is curved as indicated and the upper edge of wall I02 terminates beneath the lower end of the plate 32. Adjustably secured to the upper edge of the wall I2 is a plate I93, having a sharp ened upper edge Ills. The plate I83 is secured to one side of a plate 565 and the lower ends of the plates IE3 and Iilfi straddle the upper edge of the wall Hi2 and are slidable thereon. The sharpened edge Ills of plate I03 and the lower edge of bracket plate 82 define between them an elongated trash discharge opening m0. The opening Hill is in alignment with the path of movement of trash and lint moving'along in the inner end of duct I6.

Secured to the outer side of the sharpened plate I03, near the upper end thereof is a depending and outwardly extending bracket plate I07. See Fig. 5. Projecting from the inner side of the plate I07 at intervals therealong are a plurality of lugs I08.

Rotatably mounted in the end plates 8|] of the apparatus is a cross shaft I09. The shaft I09 is provided at intervals with fiat bottomed cross slots III which extend approximately half way through the shaft. Mounted on the shaft I09 are a plurality of blocks II2 havin threaded therethrough set screws I I3 disposed to enter the slots III and engage the fiat bottoms thereof. From this construction it will be seen that by adjusting the screws Hit the relative angularity of the blocks with respect to the shaft I09 may be determined.

Passing through each block II2 is a threaded rod I I6 havin its upper end pivotally connected to one of the lugs I98. The rods are adjustably supported in the blocks by means of nuts H6.

The shaft its projects from one end of the apparatus and is provided with an operating handle Ill. The upper end of the operating handle passes through a slot IIB provided in one leg H9 of an angle I2I carried by the adjacent end plate fill. Pivotally mounted to the leg II9 of the angle as at 122 is a bar I23. Passing through the other leg lid of the angle [H and threaded into the free end of the bar I23 is a locking screw I26. By runnin in on the set screw I26 the operating handle II! is clamped in adjusted position in the slot I I8.

Referring again to Fig. 4 of the drawing, I provide an outer wall I21 spaced from the wall 83 and the lower duct IilI. This wall defines with the parts just mentioned a space I28 for receivllig trash thrown out of the trash opening I00 defined between the sharpened edge I04 and the lower end of the plate bracket 82. The top of the space I28 is open as indicated at I29 whereby air induced into the trash opening Hill is readily supplied for that purpose.

At the bottom of the space !28 is a trough I3I in which may be placed a suitable form of trash dgszcharge apparatus, such for instance as a belt The walls 99 and IE2 curve downwardly and thence outwardly and converge adjacent their inner ends to define another constricted space i33 in the duct IOI. The wall 99 curves again downwardly at the point I34 to provide a short section I38. Another wall section I31 forms with the wall I36 a duct I38 leading to a lint fiue I39. The upper end of the wall Illla is provided with a sharpened plate 53a, similar to plate I03, together with the adjusting mechanism previously described, including a cross shaft I890 and an operating handle NM. The sharp edge Illda of the plate Hilda defines with the lower end I4I of the wall Hi2 a trash discharge opening IIll'la, similar to the trash opening I96.

The section B has a vertical wall M2 extending from beneath the plate bracket idle and terminating along the inner edge of a trough I3Ia. A front wall I271; terminates along the opposite or outer wall of the trough I3Ia, and a trash discharge belt I32a is placed in the trough. Similarly to thesection A, the walls I42 and I2'Ia define a trash receiving space I28a open at its top as at I29a.

It will be noted that in the construction just 9. described there is ample space for placingthe lint flue I39 within the confines of the apparatus. This is accomplished by supporting the lint flue on a member I43 suitably secured to the framework of the apparatus. The entire apparatus may be supported clear of the floor I lt by means of legs Mt and I41.

From the foregoing the operation of the modification of my invention just described may now be explained. Depending upon the type of gin supplying the lint and trash with the cloning stream of air, the adjustments relative to the size of the constricted portions of the ducts it and IIlI are made. The trash discharge openings I and IBM are regulated to approximately the size before mentioned. A supply of air under a pressure of approximately to inches on the Water gauge is maintained in the air chamber 93 and the lint :fiue I39 is maintained under vacuum of from one to three inches, water gauge. I adjust the movable wall sections 89 so that the air discharge nozzle or jet 95 is approximately inch wide and the air discharge nozzle 91 is approximately inch wide. Under these conditions the air entering through the opening 96 strikes the lint, and puifs or blooms the same, aiding in causing the trash therein to separate from the lint. This air enters at a velocity of approximately 10,000 feet per minute. As the comrningled stream approaches the trash discharge opening I00 it is struck by the transversely directed stream of air having a velocity of about 10,000 feet per minute. Due to its velocity the effectiveness of this jet in turning the lint is very high. However, it induces very little air into the trash discharge opening I00 and thus adds practically no tendency to draw fine trash back into the duct. The jet from the opening 91 has the beneficial effect of driving the lint onto the second cleaning opening IGIIa without loss in velocity of the stream. Further, I have discovered that this stream of air does not materially change the direction of movement of the trash.

It is also to be noted that in the modification being described the induced air entering the slots I00 and IBM is moving downwardly in the spaces I28 and I28a, in the same direction that the trash falls after being discharged from the openings. improvement over the first described modification in that fine trash more or less suspended in the spaces I28 and I280: has very little tendency to be drawn back into the lint ducts and is caused to settle onto the discharge belts in the troughs.

It will be noted that it is possible to use either of the sections A or B separately, thus obtaining the advantage just mentioned relative to hav ing the induced air entering the opening I29 or I290, move in the same direction in which the trash is discharged from the slot, namely, downwardly. The booster jet of air entering the lint duct Iii through the opening 915 and the transversely directed jet entering the same through the opening 91 are particularly effective in cleaning excessively dirty cotton, for instance machine picked cotton.

Referring to Fig. 9 I have indicated diagrammatically the way the lint and trash stream move in the ducts I6 and IBI, and the position thereof at the time it is engaged by the jets 9t and 537. Fig. 9 also indicates the position of the lint and trash adjacent the trash discharge openings Ifill and IIlUa. Due in part to the curvature of the This is of particular advantage and is an ducts it will be noted that the particles in the air-borne stream are more or less condensed against the duct wall at these points. This results in a more uniform action on the particles at the slot and therefore a more perfect separation. This is due not only to the curvatures of the ducts but also to the high velocity within the duct system and I hav found this to be advantageous in effecting separation.

Referring to Fig. 10, I show an additional feature which may be used with the apparatus shown in Figs. 1 to 4. In practice the portion of the lint duct I t immediately ahead of the cleaning apparatus is substantially horizontal. This may permit certain of the heavy trash to settle out onto the lower wall of the duct. If the cleaner is to be used with a gin having brush dofing means or with a pneumatic gin in which the doffng air is of low velocity, this settling out action becomes a more serious problem.

In order to overcome this settling out of trash and to move the entire commingled stream in duct It at a higher velocity, I slit the bottom wall of the duct It as at Ma, substantially across its width. Air under pressure of about 15 inches water gauge is supplied to the slit I l-a by means of an air pipe I5. This jet of air is directed along the lower duct wall and moves therealong any trash settled out. In some instances I note a remarkable improvement in the amount of trash removed when using the jet I ia. This feature makes my improved cleaner entirely suitable for use with brush type gins.

From the foregoing it will be apparent that I have devised an improved apparatus for separating trash from lint cotton. In actual practice I have found that the apparatus herein described is extremely effective for its intended purposes. I have further found that very little additional overall power for a ginning system embodying the same is required and. that no damage is done to the lint. With either form of the apparatus I have observed that the combination of super atmospheric pressure on the inlet end of the ducts and sub-atmospheric pressure on the outlet end thereof is essential for obtaining the best cleaning results with the apparatus shown in Figs. 1, 2 and 3. Referring to Fig. 4 it will be seen that duct HII could be led directly into the lint flue I39. With respect to pressure in the inlet ducts, when the commingled stream is delivered by a present day gin, such pressure cannot be raised very much above 1 inch water gauge because the gin will back lash, namely, lint will not be removed from the saws and wedges between the gin ribs, choking the gin. In all forms of the invention shown and described herein it will be noted that the ducts are so arranged, especially adjacent the trash discharge slots, as to reduce turbulence to the minimum. Thus, immediately ahead of each slot the several ducts curve on easy radii, with the result that the thin ribbons of commingled lint and trash are effectively acted upon by the several positive and induced streams of separating air. The radius of the curve between the adjacent ducts defining between the slots should, in all cases, be such as to reduce turbulent flow therein to the minimum, and in practice I find that the radius between the ducts I6 and ii) I, for example, should be about 1 inch.

In order to further demonstrate the increase in efficiency due to moving the cornmingled linttrash stream at relatively high velocities, I show below a table of separating efficiencies at difierent velocities. The table represents the 11 quantity of trash removed at the velocity of 3000 feet per minute as 100%. The table shows that at 3500 feet per minute 30% more trash is removed than at 3000 feet per minute, etc.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and, I, desire therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In apparatus for separating lint cotton and trash from an air-borne stream of the same, a laterally elongated relatively shallow duct into which the air-borne stream is introduced, an elongated opening in one wall of the duct, means to supply air under super-atmospheric pneumatic pressure through the elongated opening into the duct substantially parallel to the direction of movement of the lint-trash stream therein, a second duct having its inlet end angularly disposed relative to the discharge end of the first duct, there being a'laterally elongated opening in alignment with the discharge end of the first duct through which trash is discharged, means to maintain the second duct under sub-atmospheric pneumatic pressure, and means to direct a stream of air under pressure transversely of the lint-trash stream just ahead of the trash discharge opening.

2. Apparatus as defined'in claim 1 in which the air under pressure supplied to said ducts through said elongated openings is supplied from a common air supply source.

3. In lint cotton cleaning apparatus, a lint duct of substantial width and whose depth is a minor fraction of its width and having inlet and outlet sections joined together and angularly disposed with respect to each other, there being a trash outlet opening to the atmosphere at the juncture of said sections substantially in line with the inlet section, means for introducing an air-borne stream of lint cotton and trash into the inlet section, suction means connected to the outlet section, and additional means to introduce a booster stream of air at super atmospheric pressure substantially entirely across the inlet section of the duct in the direction of travel of the airborne stream. 7

4. In lint cotton cleaning apparatus, a relatively wide shallow duct having an upwardly inclined inlet section and an outlet section at an abrupt angle thereto and having a narrow elongated trash discharge slot at the juncture of the inlet and outlet sections in the outer wall of the duct substantially in line with the inlet section, means to introduce air-borne lint and trash into the inlet section under super atmospheric pressure, means to maintain the outlet section of said duct under sub-atmospheric pressure, a restricted passage in the inlet section of said duct adjacent the trash discharge slot whereby to increase the velocity of said stream and reduce its pressure adjacent said slot, a housing for the duct including a chamber into which the discharge slot opens, said chamber being open at the top to admit air from the atmosphere for introduction into the slot and having a vertical side wall extending downwardly toward the open slot to direct the air downwardly toward the slot normal to the path of the trash being discharged, a lower upwardly diverging wall for the chamber terminating below the inlet section of the duct and in spaced relation thereto to admit air from the atmosphere over said wall, and a downturned lip on the inlet section of the duct at said slot overhanging said lower Wall to direct the air down wardly.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 469,559 Groom Feb. 23, 1892 633,383 Kramer Sept. 19, 1899 661,166 'Boyd Nov. 6, 1900 977,194 James Nov. 29, 1910 1,002,131 Broome Aug. 29, 1911 1,023,750 Morscher Apr. 16, 1912 1,129,902 Reardon Mar. 2, 1915 1,660,682 Stebbins Feb. 28, 1928 1,713,371 Brennen May 14, 1929 1,994,610 I-Iuyett Mar. 19, 1935 2,372,796 Rogers et a1 Apr. 3, 1945 2,438,047 Graebe Mar. 16, 1948 2,540,348 Reed Feb. 2, 1951 

